Automatic draft stabilizer



Feb. 13, 1934. O w DRESSLER 1,947,251

AUTOMATIC DRAFT STABILIZER Filed Sept. 22, [1932 p I u I k Z0 Patented Feb. 13, 1934 STATES AUTOMATIC DRAFT STABILIZEB.

Otto W. Dressler,

Minneapolis, Minn.

Application September 22, 1932 Serial N0. 684,275

2 Claims.

My invention has for its object the provision of an extremely simple and highly eificient automatic draft stabilizer intended for general use but especially well adapted for use in connection with the smoke pipes or fiues of heating furnaces,

boilers and the like.

To the above end, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawin which illustrates the invention, like characters indicate like parts throughout the several views,

Referring to the drawing:

Fig. l is a view in side elevation showing the i5 invention embodied in the horizontal section of a smoke pipe leading from a heating furnace to a chimney, said furnace and chimney being only fragmentarily illustrated;

Fi 2 is a View in section taken on the line 22 of Fig. 1, on an enlarged scale, some parts being shown in different positions by means of broken lines;

Fig. 3 is a plan view of the invention as shown in Fig. 1, on an enlarged scale, with some parts shown in different positions by means of broken lines;

Fig. 4 is a fragmentary detail view with some parts sectioned on the line 44 of Fig. 3, on an enlarged scale; and

Fig. 5 is a view partly in elevation and partly in section taken on the line 5-5 of Fig. 3. The numeral 6 indicates a smoke pipe leadin from a heating furnace 7 to a chimney 8. Secured to the horizontal portion of the smoke pipe 85 6 is an upstanding lateral pipe section or cylindrical casing 9 having communication with the smoke pipe 6 through a hole 10 cut therein. If desired, cement or other joint-closing material may be placed between the smoke pipe 6 and casing 9 to form an air-tight joint therebetween,

as indicated at 11.

The outer or upper end of the casing 9 is closed by a cap 12 which rests on the outer edge of the respective end of said casing. This cap 12 has on its inner face an annular flange 13 telescoped into the casing 9 with a frictionfit sufliciently tight to hold the cap 12 where positioned but at the same time, free to be turned about the axis of said casing.

Formed in the cap 12, at the axis thereof, is a round air intake passageway 14 surrounded by an annular flange 15 on the outer face of said cap and by a raised annular seat 16 on the inner face of said cap. A gasket 1'7 on the seat 16 is secured thereto by any suitable means. Within the casing 9 is a round damper plate 18 normally closing the air intake passageway 14 and arranged to seat on the gasket 17. This damper plate 18 is a relatively light cast metal structure suitably ribbed to prevent warping so that said plate will set throughout its entire circumference on the gasket 17 and form a tight joint with the cap 12.

The damper plate 18 is provided with a radially projecting arm 19 comprising an inner section 20 cast therewith and an outer section 21 in the form of a rod connected thereto by screw-threads. The end portions of the arm section 20 are laterally offset from each other and on opposite sides of the cap 12. Said arm section 20 extends through an aperture 22 in the cap 12 and between a pair of diametrically opposite outstanding hinge lugs 23 on said cap to which it is secured by a hinge pin 24. The hinge for the arm 19 holds the damper plate 18 for swinging movement to and from a closed position. The outer portion of the inner arm section 20 is tapped and internally threaded to receive the screw-rod 21 which is threaded throughout its entire length,

A nut-acting weight 25, in the form of a disc, is mounted on the screw-rod 21 and by rotating said weight on the rod 21 the same may be adjusted toward or from the damper plate 18 to vary the leverage thereof. It is important to note, by reference to Fig. 5, that the passage of the screw-rod 21 through the weight 25 is eccentric to the axis thereof so that the center of gravity of the weight 25 is below the screw-rod 21 and thereby prevents the weight 25 from being accidentally turned on the screw-rod and will always remain where positioned.

The weight 25 may be positioned on the arm 19 so as to hold the damper plate 18 closed under any desired pressure capable of being exerted by the weight 25 or balanced in a partially open position. Under ordinary circumstances the weight 25 will yieldingly hold the damper plate 18 closed but as the draft through the smoke pipe 6 increases the suction produced thereby in the casing 9 will automatically open the damper plate 18. The degree to which the damper plate 18 is opened depends on the suction produced by the draft through the smoke pipe 6, and hence, the volume of the air intake through the passageway 14 to check the draft. As the draft decreases the weight 25 will automatically close the damper plate 18.

If desired, the rod 21 may be turned into or out of the arm section 20 to vary the operative length of the arm from the weight 25 to its pivot pin 24. This adjustment of the rod 21 in the arm section 20 is equivalent to adjusting the weight on the rod 21.

The automatic draft stabilizer may be set in any desired position on either side of the smoke pipe 6 from a horizontal position to a vertical position simply by turning the respective smoke pipe section about its longitudinal axis or in attaching the casing 9 to the smoke pipe 6 at the time of application. When the stabilizer is positioned oblique to vertical, as indicated by broken lines in Fig. 2, the cap 12 will be turned in the casing 9 to bring the weight 25 on the lowermost side of said cap. In positioning the stabilizer in a horizontal or nearly a horizontal position the arm section 21, which is of bendable material, is bent, as indicated in Fig. 2, to position the weight 25 so as to hold the damper plate 18 closed. While the stabilizer is shown applied to a horizontal pipe section it is evident that the same may be attached to a vertical pipe section or to a chimney and in communication with its flue.

From the above description it is evident that the automatic draft stabilizer can be set in various different positions circumferentially spaced about the axis of a pipe or flue and that the cap 12 may be turned about'an axis perpendicular to the axis of the pipe or flue so as to cause the arm 19 to project in any desired radial direction from the casing 9.

What I claim is:

1. A device of the class described comp-rising a pipe section having a substantially radial pipe extension, said pipe section being applicable to a flue or other connection for turning movement about its axis to position the pipe extension at diiierent points in a circle substantially concentric with the pipe section, a cap applied to the pipe extension and having an air passage, and a damper plate for the air passage having a radially projecting Weight-equipped arm, said arm being intermediately hinged to the cap and positively holding the damper plate except for opening and closing movements, said weight-equipped arm being under strain to close the damper plate and said damper plate being arranged to open by suction produced in the pipe extension, said cap being mounted on the pipe extension for turning movement substantially about its axis, whereby when the pipe extension is not in a vertical position the center of gravity of the damper plate and its arm may be changed, at will, by turning the cap on the pipe extension.

2. A device of the class described comprising a pipe section having a substantially radial pipe extension,'said pipe section being applicable to a flue or other connection for turning movement about its axis to position the pipe extension at different points in a circle substantially concentric with a pipe section, a cap applied to the pipe extension and. having an air passage, and a damper plate in the pipe extension arranged to seat on the inner face of the cap and close the air passage, said damper plate having an arm that extends outwardly through an aperture in the cap, said arm being hinged to the cap and positively holding the damper plate except for opening and closing movements, a weight on the outer end portion of the arm and under strain to close the damper plate, said damper plate being arranged to open by suction produced in the pipe extension, said cap being mounted on the pipe extension for turning movement substantially about its axis, whereby when the pipe extension is not in a vertical position the center of gravity of the damper plate and its arm may be changed, at will, by turning the cap on the pipe extension.

OTTO W. DRESSER. 

